Study of circulating antibodies against CD25 and FOXP3 in breast cancer

Can serum autoantibodies be a potential early detection biomarker for breast cancer in women? A diagnostic test accuracy review and meta-analysis

BACKGROUND

The increasing incidence of breast cancer necessitates the need to explore alternate screening strategies that circumvent the setbacks of conventional techniques especially among population that report earlier age at diagnosis. Serum autoantibodies is one such potential area of interest. However, their ubiquitous presence across cancer types limits its applicability to any one specific type of cancer. This review was therefore carried out to explore and consolidate available evidence on autoantibodies for early detection of breast cancer and to identify those that demonstrated a higher sensitivity.

METHODS

A diagnostic test accuracy (DTA) review was carried out to ascertain serum autoantibodies that could be used for early detection of breast cancer among women. All relevant articles that investigated the role of autoantibodies in early detection of breast cancer were included for the review. MEDLINE, Scopus, ProQuest, Ovid SP, and Cochrane Library were searched extensively for eligible studies. Quality of the included studies was assessed using Quality Assessment of Diagnostic Accuracy Studies (QUADAS)-2 tool. RevMan 5.3 was used for exploratory and MetaDTA 2019 for hierarchical analyses. The review helped identify the most frequently investigated autoantibodies and a meta-analysis further consolidated the findings.

RESULTS

A total of 53 articles were included for the final analysis that reported over a 100 autoantibodies that were studied for early detection of breast cancer in women. P53, MUC1, HER2, HSP60, P16, Cyclin B1, and c-Myc were the most frequently investigated autoantibodies. Of these P53, MUC1, HER2, and HSP60 exhibited higher summary sensitivity measures. While the individual pooled sensitivity estimates ranged between 10 and 56%, the panel sensitivity values reported across studies were higher with an estimated range of 60-87%.

CONCLUSION

Findings from the review indicate a higher sensitivity for an autoantibody panel in comparison to individual assays. A panel comprising of P53, MUC1, HER2, and HSP60 autoantibodies has the potential to be investigated as an early detection biomarker for breast cancer.

Detection of circulating natural antibodies against CD25, MUC1, and VEGFR1 for early diagnosis of non-small cell lung cancer

We previously demonstrated that a deficiency of natural antibodies against CD25, Mucin 1 (MUC1), and vascular endothelial growth factor receptor 1 (VEGFR1) could contribute to high risk of non‐small cell lung cancer (NSCLC). This study was designed to investigate whether natural IgG antibodies against POU domain class 5 transcription factor 1 (POU5F1), tumor necrosis factor‐α (TNF‐α), and the combination of CD25, VEGFR1, and MUC1 could play an anti‐tumorigenic role against developing NSCLC. An ELISA was developed in‐house to examine plasma IgG against peptide antigens derived from POU5F1, TNF‐α, and a combination of peptide antigens derived from CD25, MUC1, and VEGFR1 in 211 patients with NSCLC and 200 healthy controls. Mann–Whitney U test demonstrated that plasma IgG levels for the combination of peptide antigens derived from CD25, MUC1, and VEGFR1 were significantly lower in NSCLC patients than control subjects (Z = −12.978, P < 0.001) although plasma levels of IgG antibodies for POU5F1 and TNFα were not significantly changed. The in‐house ELISA made with the CD25‐MUC1‐VEGFR1 combination had a sensitivity of 49.6% against a specificity of 95% to detect early‐stage NSCLC. In conclusion, natural antibodies against the combination of CD25, VEGFR1, and MUC1 may be an effective biomarker for early diagnosis of NSCLC.

Further Study of Circulating Antibodies to P16, CD25 and FOXP3 in Hepatocellular Carcinoma

Purpose

It has been reported that circulating levels of IgG antibodies against p16, CD25 and FOXP3 proteins were significantly changed in patients with lung cancer, breast cancer and esophageal cancer. However, different peptide fragments appear to trigger different immune responses. This work aimed to analyze the alteration of plasma IgG for p16-derived peptide antigen called p16a, CD25-derived peptide antigen called CD25a and a FOXP3-derived antigen in hepatocellular carcinoma (HCC).

Patients and methods

An enzyme-linked immunosorbent assay (ELISA) was developed in-house to detect plasma IgG to p16a, CD25a and FOXP3 in 119 patients with HCC and 132 control subjects.

Results

Circulating levels of IgG antibodies for all three peptide antigens were significantly higher in HCC patients than control subjects (P<0.001 for all 3 assays); male patients mainly contributed to increase (P<0.01 for all 3 assays). Further analysis showed that plasma anti-p16a, anti-CD25a and anti-FOXP3 IgG levels were increased mainly in patients with intermediate and late-stage HCC (P<0.01 for both assays). Receiver operating characteristic (ROC) curve analysis showed that with a specificity of >95%, the area under the ROC curve (AUC) was 0.62 with 11.4% sensitivity for anti-p16a assay, 0.68 with 14.3% sensitivity for anti-CD25a IgG assay and 0.64 with 10.1% sensitivity for anti-FOXP3 assay. Of the three groups of HCC patients, group 3 (BCLC stage C+D) showed the best sensitivity for the detection of plasma anti-p16a and anti-FOXP3 IgG levels with an AUC of 0.66 and 0.65.

Conclusion

Circulating IgG antibody to p16a, CD25a and FOXP3 proteins may be a useful biomarker for assessment of HCC prognosis of this malignancy, especially in male patients with HCC.

Alteration of circulating natural autoantibodies to CD25-derived peptide antigens and FOXP3 in non-small cell lung cancer

Natural autoantibody is a key component for immune surveillance function. Regulatory T (Treg) cells play indispensable roles in promoting tumorigenesis via immune escape mechanisms. Both CD25 and FOXP3 are specific markers for Treg cells and their natural autoantibodies may be involved in anticancer activities. This work was designed to develop an in-house enzyme-linked immunosorbent assay (ELISA) to examine plasma natural IgG against CD25 and FOXP3 in non-small cell lung cancer (NSCLC). Compared with control subjects, NSCLC patients had significantly higher levels of plasma IgG for CD25a (Z = -8.05, P < 0.001) and FOXP3 (Z = -4.17, P < 0.001), lower levels for CD25b (Z = -3.58, P < 0.001), and a trend toward lower levels for CD25c (Z = -1.70, P = 0.09). Interestingly, the anti-CD25b IgG assay had a sensitivity of 25.0% against a specificity of 95.0% in an early stage patients (T1N0M0) who showed the lowest anti-CD25b IgG levels among 4 subgroups classified based on staging information. Kaplan-Meier survival analysis showed that patients with high anti-FOXP3 IgG levels had shorter survival than those with low anti-FOXP3 IgG levels (χ2 = 3.75, P = 0.05). In conclusion, anti-CD25b IgG may be a promising biomarker in terms of screening individuals at high risk of lung cancer.

Further study of circulating IgG antibodies to CD25-derived peptide antigens in nonsmall cell lung cancer

A recent study reported that circulating antibodies to CD25-derived peptide antigens were significantly higher in patients with nonsmall cell lung cancer (NSCLC) than control subjects. The present study was, thus, undertaken to replicate the initial finding with different sample sets. An in-house ELISA was applied to determine circulating IgG antibodies to linear peptide antigens derived from CD25. A total of 111 patients with NSCLC and 216 control subjects were recruited and divided into the discovery sample (51 vs 108) and the validation sample (60 vs 108) based on the time of sampling. Student's t test showed that circulating anti-CD25 IgG levels were significantly higher in the patient group than the control group (t = 2.23, P = 0.027) and the validation sample replicated this finding (t = 3.31, P = 0.0012), generating a combined P value of 0.0004 (χ(2) = 20.8, df = 4). Fisher's combining probability revealed that patients with stage IV NSCLC had a significant increase in anti-CD25 IgG levels compared with control subjects (χ(2) = 22.1, df = 4, P = 0.0002) but those with the other three stages did not. This study suggests that circulating anti-CD25 IgG antibodies may have prognostic rather than early diagnostic values for lung cancer.

Immunotherapy for the treatment of breast cancer

Decades of research are now leading to therapeutics that target the molecular mechanisms of the cancer-specific immune response. These therapeutics include tumor antigen vaccines, dendritic cell activators, adjuvants that activate innate immunity, adoptive cellular therapy, and checkpoint blockade. The advances in targeted immunotherapy have led to clinical advances in the treatment of solid tumors such as melanoma, prostate cancer, lung cancer, and hematologic malignancies. Preclinical and translational studies suggest that patients with breast cancer may also benefit from augmenting effective immune responses. These results have led to early-phase clinical trials of tumor antigen vaccines, adjuvants, and combinations of checkpoint inhibitor blockade to boost breast cancer-specific immunity in patients. This review focuses on the current and emerging development of cancer immunotherapy for breast cancer.

Investigation of circulating antibodies to ANXA1 in breast cancer

Our recent work demonstrated that circulating levels of IgG antibody to linear peptide antigens derived from annexin A1 (ANXA1) were significantly increased in lung cancer. The present study was then undertaken to test whether circulating anti-ANXA1 antibodies were also altered in breast cancer. An enzyme-linked immunosorbent assay was developed in-house to determine circulating IgG against ANXA1-derived peptide antigens in 152 female patients with breast cancer and 160 female control subjects. Student's t test revealed that patients with breast cancer had significantly higher levels of anti-ANXA1 IgG than control subjects (t = 4.75, P < 0.0001). Receiver operating characteristic (ROC) analysis showed that the area under the ROC curve was 0.73 with 95% confidence interval (CI) 0.67-0.78, and the sensitivity of anti-ANXA1 IgG assay was 23.2% against the specificity of 90%. The levels of anti-ANXA1 IgG did not appear to be stage-dependent, and Pearson correlation analysis showed no correlation between the anti-ANXA1 IgG levels and the stages of breast cancer (r = -0.02, df = 149, P = 0.796). This work suggests that circulating IgG for ANXA1-derived peptide antigens may have both diagnostic and prognostic values for breast cancer although further screening is needed to identify more such peptide antigens derived from tumor-associated antigens.

Use of autoantibodies to detect the onset of breast cancer

The widespread use of screening mammography has resulted in increased detection of early-stage breast disease, particularly for in situ carcinoma and early-stage breast cancer. However, the majority of women with abnormalities noted on screening mammograms are not diagnosed with cancer because of several factors, including radiologist assessment, patient age, breast density, malpractice concerns, and quality control procedures. Although magnetic resonance imaging is a highly sensitive detection tool that has become standard for women at very high risk of developing breast cancer, it lacks sufficient specificity and costeffectiveness for use as a general screening tool. Therefore, there is an important need to improve screening and diagnosis of early-invasive and noninvasive tumors, that is, in situ carcinoma. The great potential for molecular tools to improve breast cancer outcomes based on early diagnosis has driven the search for diagnostic biomarkers. Identification of tumor-specific markers capable of eliciting an immune response in the early stages of tumor development seems to provide an effective approach for early diagnosis. The aim of this review is to describe several autoantibodies identified during breast cancer diagnosis. We will focus on these molecules highlighted in the past two years and discuss the potential future use of autoantibodies as biomarkers of early-stage breast cancer.